Stress incontinence is caused primarily by increased intra-abdominal pressure. One surgical method for treating this condition involves suspension of the bladder neck for repositioning in the correct, fixed retropubic position so that there is no voiding of the bladder under stress. Several relatively non-invasive surgical procedures for bladder neck suspension are described in Hadley et at., Urologic Clinics of North America, Vol. 12, No. 2, p. 291 (1985).
In the original Pereyra method (West. J. Surg., 67: 223, 1959), a needle is passed from a suprapubic incision to an incision in the vagina near the bladder neck. Stainless steel suture wire is passed several times from the bladder neck to the suprapubic incision to suspend the bladder neck. The Cobb-Radge method inserts the needle from below through the vaginal incision. The Stamey procedure (Ann. Surg., 192: 465, 1980) uses an endoscope to prevent the surgical needle from puncturing the bladder. Dacron vascular graft is used to anchor nylon suture in the periurethral tissue. Finally, in the Raz method (Urology, 17: 82, 1981) the surgeon inserts his or her finger through the vaginal incision to guide the suspension needle and avoid penetration of the bladder by the needle. The sutures are anchored by threading through tissue of the vaginal wall and tissue in the suprapubic area.
A major problem encountered during surgical needle suspension procedures such as described above is the correct positioning of the bladder neck and the urethra such that the position of the bladder neck with respect to the bladder is high enough to avoid incontinence under stress while not too high to prevent proper bladder voiding.
Over the years, various techniques have been developed using pubic bone fixation to suspend sutures. To facilitate the anchoring of the suspending suture to the pubic bone with minimal soft tissue dissection, bone anchors with attached sutures are passed into a hole drilled in the pubic bone. Currently, a surgeon may place the tip of his or her index finger on the pubic bone anchor and tie down the suspending suture over his or her index finger using the approximate dimension of the distal pulp of the index finger to deliver a certain degree of tension to the suspending sutures. Once the finger is withdrawn, this leaves a small mount of slack in the suture which permits a quasi-controlled and limited suspension of the bladder neck when suspended in this way. The slack is generally acceptable because of the large volume of pubocervical fascia lending support to the bladder neck. It is, however, relatively easy to place excessive tension on the bladder neck. Chronic urine retention with endoscopic bladder neck suspension has been reported in as many as 5 to 18.9 percent of patients. Excessive tension with overcorrection of the bladder neck is also known to account for bladder instability.
As an alternative to forming a suture sling by tying down against the index finger, there is a need for a suture tensioner for providing consistent, repeatable mounts of tension in the suture sling. A reproducible technique of tying the suspending suture is not presently available.